A foreign object such as a gallstone, a pancreatic stone, or a thrombus is sometimes produced in a tubular organ such as the bile duct, the pancreatic duct, the ureter, a blood vessel, or another body cavity of the human body. Therefore, an operation of capturing such a foreign object and removing it from a body cavity is performed.
For example, Patent Literature 1 discloses a treatment tool for a tubular organ, including: a tube; a wire which is inserted through the tube; a basket which is formed into a tubular shape by knitting metal wire members, and in which base end portions thereof are bundled together and coupled to a distal end portion of the tube, and distal end portions are bundled and coupled to a distal end portion of the wire; and a handle portion which holds a base end portion of the tube, and which holds a base end portion of the wire in a manner that the wire is movable relative to the tube.
The basket has an approximate spindle shape in which the ends of the tubular member are reduced in diameter into a tapered shape. In the basket, the wire is placed in the middle, the distal end side has a mesh shape formed by plural metal wire members, the plural metal wire members are bundled together to form plural bundled portions in the base end side, and openings are formed between them.
In an actual use of the treatment tool, the handle portion is operated to pull the wire toward the proximal side to expand the diameter of the basket, a foreign object is received through the opening to be captured, the basket is then moved to the duodenum or the like, the handle portion is operated in the position to push and pull the wire, thereby expanding and contracting the diameter of the basket, and the foreign object is discharged through the opening of the basket.